It is just the rom portion of the update. This already is rooted and has busybox superuser and the lot preinstalled. This will not install the updated radio and is installed just like flashing a rom.

In the thread over at XDA I think I saw someone post just the radio update. If you find that file you should be able to update the radio using unrevoked forever, keep your clockwork recovery, then install the rom...

Someone correct me if I am wrong as this is about the limit of my knowledge of all this stuff.